The present invention relates to a liquid container, a component for forming a liquid container, and a method for producing a liquid container.
Conventionally, an ink jet recording apparatus has been widely used as a liquid ejecting apparatus, which ejects liquid to a target. In greater detail, this ink jet recording apparatus comprises a carriage, a recording head mounted on the carriage, and an ink cartridge containing ink as liquid. Printing is carried out on a recording medium by ejecting ink from nozzles formed on the recording head while moving the carriage relative to the recording medium and providing ink to the recording head from the ink cartridge.
Moreover, in such an ink jet recording apparatus, in order to reduce the load on a carriage, or to make the apparatus compact and thin, there is a structure, in which an ink cartridge is not mounted on a carriage (a so-called off-carriage type). Such an ink cartridge typically includes an ink pack containing ink, and a case accommodating the ink pack.
Conventionally, an ink pack 180 with an outlet portion 181 shown in FIG. 25 is known as such an ink pack (For example, see Japanese Patent Application Publication No. 2002-192739). In detail, this outlet portion 181 is held in an opening of a bag portion 182 of the ink pack 180 in a manner being sandwiched, and discharges the ink contained in the bag portion 182. This outlet portion 181 is provided with a first tube body 183, and a second tube body 184.
An annular rubber packing 185, and a first valve body 187 capable of sealingly closing an opening of the rubber packing 185 by a biasing force of a coil-shaped spring component 186 are provided inside the first tube body 183. When an ink inlet tube 188 connected to an ink supply tube (not show) is inserted into the outlet portion 181, a first valve body 187 is pressed and moved by the ink inlet tube 188, and then the opening of the rubber packing 185 is opened.
In addition, in the state where the ink inlet tube 188 is not inserted into the outlet portion 181, the first valve body 187 abuts and sealingly closes the opening of the rubber packing 185 so that the ink in the ink pack 180 does not leak to the outside.
The second tube body 184 is fixed by press-fitting into the first tube body 183. A valve body accommodating chamber 191 is defined by the second tube body 184 and the first tube body 183. This valve body accommodating chamber 191 movably accommodates a disc-shaped second valve body 192. This second valve body 192 abuts a valve seat 193 provided in the second tube body 184 so as to sealingly close a tube path of the outlet portion 181. On the other hand, when the pressure of the ink in the ink pack increases, the second valve body 192 moves away from the valve seat 193 so as to open the path of the outlet portion 181. Thus, this second valve body 192 and the seat 193 construct a valve device 194, this valve device 194 functions as a check valve, which allows the flow of ink only from an inside of the ink pack 180 to the outside.
In order to supply ink from the ink pack 180 having the outlet portion 181 as constructed above to a recording head, an ink inlet tube 188 is first inserted into the outlet portion 181, then the pressure of the ink in the ink pack 180 is increased by pressing the bag portion 182 or the like. As a result, the second valve body 192 moves away from the valve seat 193, and the ink in the ink pack 180 is supplied to the recording head through the outlet portion 181 and an ink supply tube.
The ink pack 180 having the outlet portion 181 as mentioned above has the following advantages: That is, for example, even if a user forcedly moves the first valve body 187 with a screw driver, etc., the valve device 194 functions as a check valve. Accordingly, this can prevent leakage of the ink in the ink pack 180 to the outside because the movement of the first valve body 187 by such user's operation causes ink in the interior of the first tube body 183 to attempt to flow into the inside of the ink pack 180 but this relatively strong or quick reverse flow of ink instantaneously move the second valve body 192 to seat on, the valve seat 193. Also, this can prevent the outside air and so on associated with such relatively strong or quick reverse flow from flowing into the ink pack 180, to thereby maintain the degassed rate or cleanliness of the ink in the ink pack 180.
In addition, the valve device 194 functioning as a check valve may permit a slight or slow reverse flow which does not cause the entry of the outside air and so on into the ink pack 180, and which would be occasionally caused, for example, during printing.
The outlet portion 181 is required to maintain high performance of the valve device 194 functioning as a check valve, and therefore to improve airtightness of the valve body accommodating chamber 191. As one of methods for improving airtightness of the valve body accommodating chamber 191, heat-crimping is used to fix the first tube body 183 and the second tube body 184 in a tight fit state to form the valve body accommodating chamber 191.
However, since recent tendency is directed toward a case in which both of the first tube body 183 and second tube body 184 are formed of synthetic resin or the like such as plastic, and since both of the first tube body 183 and the second tube body 184, in this case, are rigid, the aforementioned method suffers from a possibility that unevenness in dimension of the first and second tube bodies 183 and 184, and thus unevenness in airtightness of the valve body accommodating chamber 191 tends to appear. This deteriorates the performance of the second valve body 192 as a check valve.
The present invention aims at solving the above problem, and its object is to provide a liquid container, a component for forming a liquid container, and a method for producing the liquid container capable of maintaining constant performance of a check valve disposed in the liquid container.
Another object of the present invention is to provide a liquid container having a check valve that can more reliably prevents the flow of outside air or the like into its inside.
Yet another object of the present invention is to ease injection of ink into a liquid container having a check valve.